Fournier E
Département de physiologie, faculté de médecine Pitié-Salpêtrière, université Pierre-et-Marie-Curie-Paris-6, 91, boulevard de l'Hôpital, 75013 Paris, France.
Rev Neurol (Paris). 2009 Dec;165(12):1127-33. doi: 10.1016/j.neurol.2009.07.003.
The anatomic complexity of the brachial plexus makes its electrophysiological exploration difficult. Electrodiagnosis nevertheless plays a crucial role in assessing brachial plexopathies, particularly in the perspective of post-traumatic surgical reconstructions. The evaluation aims to locate as precisely as possible injuries within the plexus, as well as to determine their severity and capacity for recovery. This requires various sensory nerve conduction studies and needle EMG recordings of "marker" muscles. Plexopathies differ from radiculopathies by altered sensory nerve responses and unaltered functional innervation of paracervical muscles. We propose to simplify the exploration of brachial plexopathies by following some practical rules derived from a reanalysis of the brachial plexus anatomic sketch. Two main simplification rules can be deduced from an analysis of the anatomic sketch. First it would be judicious to associate the plexopathies involving a single element of the brachial plexus with distinct etiological and symptomatic patterns according to the altered element, as one does for peripheral nerve and root pathologies. The second proposal relies on the observation that each supraclavicular "truncal" element (upper, middle, or lower) of the brachial plexus results from reunion of cervical root nerves and behaves like a "super-root" for the upper limb, while each infraclavicular "cord" element (posterior, lateral, or medial) is the sum of two or more peripheral nerves and behaves like a "super-nerve". Accordingly, the motor and sensory abnormalities associated with the lesion of a single plexus branch may occupy a clinical and electrophysiological territory that recovers those of its constituants. Except the unaltered paracervical muscles, it is useful to reduce the topographical semiology of truncal lesions to well-known cervical radiculopathies (upper trunk neuropathy to C5 and C6 associated radiculopathies, middle trunk neuropathy to C7 radiculopathy, lower trunk neuropathy to C8 and T1 associated radiculopathies); and that of cord lesions to well-known mononeuropathies of the upper limb (for example, a posterior cord neuropathy may be considered as a full radial mononeuropathy associated with an axillary one). This method of simplification allows to demystify the brachial plexopathies and to facilitate their comprehension and exploration.
臂丛神经的解剖结构复杂，这使得对其进行电生理检查具有一定难度。然而，电诊断在评估臂丛神经病变中起着至关重要的作用，尤其是在创伤后手术重建方面。评估的目的是尽可能精确地定位臂丛神经内的损伤，并确定其严重程度和恢复能力。这需要进行各种感觉神经传导研究以及对“标志性”肌肉进行针极肌电图记录。臂丛神经病变与神经根病变的不同之处在于感觉神经反应改变以及颈旁肌肉的功能神经支配未改变。我们建议通过遵循从重新分析臂丛神经解剖示意图得出的一些实用规则来简化臂丛神经病变的检查。从解剖示意图的分析中可以推导出两条主要的简化规则。首先，明智的做法是根据受累部位的不同，将涉及臂丛神经单一成分的病变与不同的病因和症状模式联系起来，就像处理周围神经和神经根病变一样。第二条建议基于这样的观察结果，即臂丛神经的每个锁骨上“干”成分（上干、中干或下干）是由颈神经根神经汇合而成，对上肢而言其作用类似于一个“超级神经根”，而每个锁骨下“束”成分（后束、外侧束或内侧束）是两条或更多周围神经的总和，其作用类似于一条“超级神经”。因此，与单个臂丛神经分支损伤相关的运动和感觉异常可能占据一个临床和电生理区域，该区域与其组成部分的区域相对应。除了颈旁肌肉未受影响外，将干病变的局部症状学简化为众所周知的颈神经根病变（上干神经病变对应C5和C6相关的神经根病变，中干神经病变对应C7神经根病变，下干神经病变对应C8和T1相关的神经根病变）是有用的；将束病变的局部症状学简化为众所周知的上肢单神经病（例如，后束神经病变可被视为与腋神经病变相关的完全性桡神经单神经病）。这种简化方法有助于揭开臂丛神经病变的神秘面纱，便于对其进行理解和检查。
